Naslov
The effects of SMS 201-995 on anti CD3 and dexamethasone-induced apoptosis in thymus

Autori
Trobonjača, Zlatko ; Radošević-Stašić, Biserka ; Rukavina, Daniel

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Annual meeting of the Croatian Immunological Society, Periodicum Biologorum 99 (1997), suppl. 2 / Vitale, Branko - Zagreb : Hrvatsko prirodoslovno društvo, 1997, 19-19

Skup
Annual meeting of the Croatian Immunological Society

Mjesto i datum
Zagreb, Hrvatska, 06.11.1997. - 07.11.1997

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
SMS 201-995; dexamethasone; anti CD3-induced apoptosis; thymus; mice

Sažetak
Activation of immature thymocytes via TCR as well as exposure to glucocorticoids, such as dexamethasone, results in apoptosis. In vivo administration of anti-CD3 antibodies to mice induces programmed cell death predominantly in double positive (CD4+CD8+), CD3low cortical and CD3intermediate medullar cell subset, that is analogous to the antigen-induced negative selection of thymocytes, capable of recognizing self antigens. The main event in negative selection process is TCR-CD3 occupancy via TCR-MHC complex interactions, that leads to the clonal deletion. This process is additionally regulated through different intercellular contacts and humoral factors. Since the expression of the somatostatin gene mRNA was found in thymus epithelial cells that exhibit bell-shaped response to dexamethasone administration, in the present study we investigated the influence of somatostatin analogue SMS 201-995 to apoptosis induced by anti-CD3 antibodies and dexamethasone in immature thymocytes of BALB/c mice. Phenotypic analysis of double positive cells and nucleic fragmentation in thymus of mice injected with 10 mg/kg/b.w. of SMS and anti-CD3 or dexamethasone were estimated 24, 48 and 72 hours, as well as, 5 and 15 days after treatment. Thymocyte phenotype was determined by direct immunofluerescence technique, and nucleic fragmentation by cell cycle analysis gating the region left from G0/G1 peak.The data have shown that SMS can depress sensitivity to apoptosis of thymocytes induced by anti-CD3 antibodies. SMS reduced the decrease of double-positive cells induced with anti-CD3 injection. Additionally, the level of nucleic fragmentation is also reduced after combined treatment with SMS and anti-CD3. The data point to the possibility that somatostatin is involved in processes of thymocyte maturation and clonal deletion of self-reactive cells.

Izvorni jezik
Engleski

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